Cross-chain bridging and atomic swap protocol Garden Finance temporarily took its app offline after blockchain security firm Blockaid reported an exploit targeting the protocol’s hash time-locked contracts (HTLC) across four blockchain networks.
On Sunday, Blockaid said an attacker drained about $450,000 in USDT from Garden’s HTLC contracts on Ethereum, Base, Arbitrum and BNB Smart Chain. HTLCs are time-bound escrow contracts that Garden uses to facilitate atomic swaps between Bitcoin and assets on other networks.
Blockaid described the exploit as ongoing when it published its alert but did not disclose the suspected vulnerability or say whether the incident affected user funds. Blockaid’s alert included addresses associated with the attacker and the affected contracts.
Garden said separately that it had detected “unusual activity” and was conducting a full investigation while its app remained temporarily offline.
Garden Finance and Blockaid acknowledged Cointelegraph’s request for comments.
The incident follows an October 2025 breach in which an attacker stole about $11.4 million after compromising the operating environment of one of Garden’s solvers. Garden said that breach did not affect its protocol contracts or put user funds at risk.